1. Technical Field
The present invention relates to flexible printed circuit boards (FPCBs) and, more specifically, relates to flexible printed circuit board base films, flexible laminates made from the flexible printed circuit board base films, and FPCBs made from the flexible laminates.
2. Discussion of Related Art
Flexible printed circuit boards (FPCBs) are widely used in various electronic devices such as mobile phones, printing heads, and hard disk drives for providing electrical transmission to moving parts, due to its excellent flexibility. With the development of electronic technology, FPCBs are required to have high circuit density and multilayer FPCBs are used to replace single sided or doubled sided FPCBs.
A thermal dissipating ability of an FPCB is not a concern when the FPCB is single sided or double sided, but the thermal dissipating ability becomes a big issue in multilayer FPCBs, especially for high density multilayer FPCBs. Generally, FPCBs are made from flexible copper clad laminates, which include a flexible printed circuit board base film and a copper layer formed on the flexible printed circuit board base film. A typical flexible printed circuit board base film is polyimide film. Polyimide has excellent flexibility. However, polyimide has poor coefficient of heat conductivity.
Therefore, there is a desire to provide a flexible printed circuit board base film having improved thermal dissipating ability.